Some of the following sentences are used with any + singular countable nouns, but some are used with any + plurals. Could anybody tell me why, please?

any + singular countable noun
1. Any fog will clear by noon.
2. You can borrow any book you like.
3. When you make a late booking, you doní know where youíre going to go, do you?
It could be any destination.
4. I do not like any child.
5. Any child could do that.

any + plural countable noun
6. You could choose any colours we wanted.
7. If you find any blackberries, keep some for me.
8. Perhaps you could correct any mistakes Iíve made.

Thanks.